The dentate gyrus is part of the hippocampus and/or hippocampal formation, as some texts include the latter structure in the former or vice versa. The dentate gyrus is thought to contribute to the formation of new episodic memories, the spontaneous exploration of novel environments, and other functions. It is notable as being one of a select few brain structures currently known to have high rates of neurogenesis in adult rats (other sites include the olfactory bulb and cerebellum).